Aha! This one I have solved. Or at least found a workaround for. My Zen 4GB (not Vision) does the same thing. To stop the deleting and re-uploading of tracks, force a rebuild of the tracks by doing a Cleanup. On mine, I stick a paper clip or something into the reset hole, hold the play button, then power up the unit to get to this menu. I have done it so often that I can almost do it one-handed. Once the cleanup is done, do a reboot and the Rebuilding... screen will appear. After that, you may still see duplicate tracks in the window (no idea how to stop this), but you won't have to wait while things are deleted and re-uploaded. Be aware that you lose your customizations when you do a cleanup. My Zen displays this behavior on about every third synchronization, so I have given up on ever having any color scheme but the default red. It is growing on me.